Buzzfeed:

Apple is no stranger to killing things people use all the time — and even love. But the headphone jack? It’s on a whole other level than disc drives or ports named after their number of pins. The headphone jack predates not only Apple, but computers themselves. And it is ubiquitous. So, when you’re killing a century-old standard around which the entire audio industry developed, it’s wise to take precautions.

Another good look at Apple’s reasoning behind killing the headphone jack.